On Aug 8, 2011, at 5:14 PM, Owen DeLong wrote: > I'm sure there will be platforms that end up on both sides of this question.
I know of no asic in a switch that claims to support ipv6 that does it this way... That would tend to place you at a competitive disadvantage to broadcom/marvell/fulcrum/juniper/cisco if you implemented it that way... it's easier I imagine to simply reduce the size of the fib... given that switches routinely have to forward to neighbors on /126 or /127 prefix links I think that would be something of a mistake. > YES: We made a less expensive box by cutting the width of the TCAM required > in half > NO: We spared no expense and passed the costs (and a nice profit margin) on > to you so > that you can do whatever you like in IPv6 at wire speed. > > I'm sure the market will chose products from both sides of the line for the > same reasons. > > Owen > > On Aug 8, 2011, at 4:34 PM, Randy Carpenter wrote: > >> >> I heard at one time that hardware manufacturers were likely to route in >> hardware only down to a /64, and that any smaller subnets would be subject >> to the "slow path" as ASICs were being designed with 64-bit address tables. >> I have no idea of the validity of that claim. Does anyone have any concrete >> evidence for or against this argument? >> >> If true, it would make /64s even more attractive. >> >> -Randy >> >> >> ----- Original Message ----- >>> we assign /112 per "end user vlan (or server)" at this moment... >>> works >>> perfectly fine (and thats even "a bit too big"). >>> >>> - nobody wants to use dynamic ips on -servers- or -router links- >>> anyway >>> >>> i -really- can't see why people don't just use subnets with just the >>> required number of addresses. >>> >>> take one /64 (for /64's sake ;), split it up into subnets which each >>> have >>> the required number of addresses (lets say you have 2-4 addresses for >>> each >>> bgp/router link, so you simply split it up into subnets that size) >>> >>> etc. >>> >>> no need to use /64 for -everything- at all, just because it fits >>> (ethernet) mac addresses (as if ethernet will be around longer than >>> ipv6 >>> ha-ha, someone will come up with something faster tomorrow and then >>> its >>> bye bye ethernet, the 10ge variant is getting slow, and the 100ge >>> variant >>> is not even standardized yet, and trunking is a bottleneck ;) >>> >>> we don't use /24's for -everything- on ipv4 now do we :P >>> >>> (oh wait, there once was a time where we did.. due to another >>> retarded >>> semi-automatic configuration thingy, called RIP , which also only >>> seemed >>> to understand /24 or bigger ;) >>> >>> -- >>> Greetings, >>> >>> Sven Olaf Kamphuis, >>> CB3ROB Ltd. & Co. KG >>> ========================================================================= >>> Address: Koloniestrasse 34 VAT Tax ID: DE267268209 >>> D-13359 Registration: HRA 42834 B >>> BERLIN Phone: >>> +31/(0)87-8747479 >>> Germany GSM: >>> +49/(0)152-26410799 >>> RIPE: CBSK1-RIPE e-Mail: s...@cb3rob.net >>> ========================================================================= >>> <penpen> C3P0, der elektrische Westerwelle >>> http://www.facebook.com/cb3rob >>> ========================================================================= >>> >>> Confidential: Please be advised that the information contained in >>> this >>> email message, including all attached documents or files, is >>> privileged >>> and confidential and is intended only for the use of the individual >>> or >>> individuals addressed. Any other use, dissemination, distribution or >>> copying of this communication is strictly prohibited. >>> >>> >>> On Mon, 8 Aug 2011, Owen DeLong wrote: >>> >>>> >>>> On Aug 7, 2011, at 4:26 PM, Jeff Wheeler wrote: >>>> >>>>> On Sun, Aug 7, 2011 at 6:58 PM, Mark Andrews <ma...@isc.org> >>>>> wrote: >>>>>> So you want HE to force all their clients to renumber. >>>>> >>>>> No. I am simply pointing out that Owen exaggerated when he stated >>>>> that he implements the following three practices together on his >>>>> own >>>>> networks: >>>>> * hierarchical addressing >>>>> * nibble-aligned addressing >>>>> * /48 per access customer >>>>> >>>>> You can simply read the last few messages in this thread to learn >>>>> that >>>>> his recommendations on this list are not even practical for his >>>>> network today, because as Owen himself says, they are not yet able >>>>> to >>>>> obtain additional RIR allocations. HE certainly operates a >>>>> useful, >>>>> high-profile tunnel-broker service which is IMO a very great asset >>>>> to >>>>> the Internet at-large; but if you spend a few minutes looking at >>>>> the >>>>> publicly available statistics on this service, they average only >>>>> around 10,000 active tunnels across all their tunnel termination >>>>> boxes >>>>> combined. They have not implemented the policies recommended by >>>>> Owen >>>>> because, as he states, a /32 is not enough. >>>>> >>>>> Do I think the position he advocates will cause the eventual >>>>> exhaustion of IPv6? Well, let's do an exercise: >>>>> >>>>> There has been some rather simplistic arithmetic posted today, >>>>> 300m >>>>> new subnets per year, etc. with zero consideration of >>>>> address/subnet >>>>> utilization efficiency within ISP networks and individual >>>>> aggregation >>>>> router pools. That is foolish. We can all pull out a calculator >>>>> and >>>>> figure that 2000::/3 has space for 35 trillion /48 networks. That >>>>> isn't how they will be assigned or routed. >>>>> >>>>> The effect of 2011-3 is that an out-sized ISP like AT&T has every >>>>> justification for deciding to allocate 24 bits worth of subnet ID >>>>> for >>>>> their "largest POP," say, one that happens to terminate layer-3 >>>>> services for all customers in an entire state. They then have >>>>> policy >>>>> support for allocating the same sized subnet for every other POP, >>>>> no >>>>> matter how small. After all, the RIR policy permits them to >>>>> obtain >>>>> additional allocations as soon as one POP subnet has become full. >>>>> >>>>> So now you have a huge ISP with a few huge POPs, and a lot of >>>>> small >>>>> ones, justified in assigning the same size aggregate prefix, >>>>> suitable >>>>> for 2^24 subnets, to all those small POPs as well. How many >>>>> layer-3 >>>>> POPs might this huge ISP have? Any number. It could be every >>>>> central >>>>> office with some kind of layer-3 customer aggregation router. It >>>>> could even be every road-side hut for FTTH services. Perhaps they >>>>> will decide to address ten thousand POPs this way. >>>>> >>>>> Now the nibble-aligned language in the policy permits them to >>>>> round up >>>>> from 10,000 POPs to 16 bits worth of address space for "POP ID." >>>>> So >>>>> AT&T is quite justified in requesting: >>>>> 48 (customer subnet length) - 24 (largest POP subnet ID size) - >>>>> 16 >>>>> (POP ID) == a /8 subnet for themselves. >>>>> >>>> Right up until you read: >>>> >>>> 6.5.3 (d): >>>> If an LIR has already reached a /12 or more, ARIN will >>>> allocate a single additional /12 rather than continue >>>> expanding nibble boundaries. >>>> As you can see, there is a safety valve in the policy at /12 for >>>> just >>>> this reason. >>>> >>>> >>>>> Now you can see how this policy, and addressing scheme, is utterly >>>>> brain-dead. It really does put you (and me, and everyone else) in >>>>> real danger of exhausting the IPv6 address space. All it takes is >>>>> a >>>>> few out-sized ISPs, with one large POP each and a bunch of smaller >>>>> ones, applying for the maximum amount of address space permitted >>>>> them >>>>> under 2011-3. >>>>> >>>> >>>> Even by your calculations, it would take 256 such outsized ISPs >>>> without >>>> a safety valve. With the safety valve that is built into the policy >>>> at /12, >>>> it would take 4,096 such ISPs. I do not believe that there are more >>>> than >>>> about 20 such ISPs world wide at this time and would put the >>>> foreseeable >>>> likely maximum at less than 100 due to the need for customers to >>>> support >>>> such outsized ISPs and the limited base that would have to be >>>> divided >>>> among them. >>>> >>>> Owen >>>> >>>> >>> >>> >>> >